:root {
  color-scheme: dark;
  --bg: #111312;
  --surface: #191c1a;
  --surface-2: #202421;
  --line: #343a35;
  --line-strong: #4b554d;
  --text: #f2f5f2;
  --muted: #a7afa9;
  --faint: #747d77;
  --green: #7ee0a8;
  --green-dark: #142a1d;
  --yellow: #efc76f;
  --yellow-dark: #2b2517;
  --red: #ef8a85;
  --red-dark: #301b1a;
  --blue: #81b7f4;
  --mono: "JetBrains Mono", monospace;
  --sans: "Noto Sans SC", system-ui, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-width: 320px;
  min-height: 100vh;
  background-color: var(--bg);
  background-image:
    linear-gradient(rgba(126, 224, 168, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(126, 224, 168, 0.035) 1px, transparent 1px);
  background-size: 32px 32px;
  color: var(--text);
  font-family: var(--sans);
  letter-spacing: 0;
}
button, textarea, input { font: inherit; }
button { color: inherit; }
button:focus-visible, textarea:focus-visible, a:focus-visible { outline: 2px solid var(--green); outline-offset: 3px; }
a { color: inherit; text-decoration: none; }
svg { width: 18px; height: 18px; flex: none; }
[hidden] { display: none !important; }

.app-shell { width: min(1180px, 100%); margin: 0 auto; padding: 0 28px 56px; }
.topbar { height: 72px; display: grid; grid-template-columns: 1fr auto auto; align-items: center; gap: 18px; border-bottom: 1px solid var(--line); }
.brand { display: inline-flex; align-items: center; gap: 12px; width: fit-content; }
.brand-mark { display: grid; place-items: center; width: 34px; height: 34px; border: 1px solid var(--green); border-radius: 6px; color: var(--green); font: 600 18px var(--mono); }
.brand strong, .brand small { display: block; }
.brand strong { font-size: 15px; }
.brand small { margin-top: 1px; color: var(--faint); font: 400 9px var(--mono); }
.topbar-status { display: inline-flex; align-items: center; gap: 8px; color: var(--muted); font-size: 13px; }
.status-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--yellow); box-shadow: 0 0 0 3px rgba(239,199,111,.12); }
.icon-button { display: inline-grid; place-items: center; width: 38px; height: 38px; padding: 0; border: 1px solid var(--line); border-radius: 6px; background: transparent; cursor: pointer; }
.icon-button:hover { background: var(--surface-2); border-color: var(--line-strong); }

.mode-tabs { display: flex; gap: 4px; padding: 14px 0; border-bottom: 1px solid var(--line); }
.mode-tab { min-height: 40px; display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 8px 14px; border: 1px solid transparent; border-radius: 6px; background: transparent; color: var(--muted); cursor: pointer; }
.mode-tab:hover { color: var(--text); background: var(--surface); }
.mode-tab.is-active { color: var(--text); border-color: var(--line); background: var(--surface-2); }
.tab-count { min-width: 20px; height: 20px; display: inline-grid; place-items: center; padding: 0 5px; border-radius: 10px; background: var(--green-dark); color: var(--green); font: 600 11px var(--mono); }

.view { display: none; padding-top: 46px; }
.view.is-visible { display: block; }
.workspace-head { display: flex; align-items: flex-end; justify-content: space-between; gap: 28px; margin-bottom: 30px; }
.workspace-head.compact { align-items: flex-start; }
.eyebrow { margin: 0 0 8px; color: var(--green); font: 600 11px var(--mono); text-transform: uppercase; }
h1, h2, h3, p { overflow-wrap: anywhere; }
h1 { max-width: 720px; margin: 0; font-size: clamp(28px, 4vw, 44px); line-height: 1.18; letter-spacing: 0; }
h2 { margin: 0; font-size: 22px; line-height: 1.35; }
h3 { margin: 0; font-size: 16px; }
.subcopy { max-width: 700px; margin: 12px 0 0; color: var(--muted); line-height: 1.75; }
.session-target { min-width: 142px; border-left: 2px solid var(--green); padding: 7px 0 7px 18px; }
.session-target span, .session-target strong { display: block; }
.session-target span { color: var(--muted); font-size: 12px; }
.session-target strong { margin-top: 3px; font: 600 25px var(--mono); }

.dashboard-grid { display: grid; grid-template-columns: minmax(0, 1.65fr) minmax(270px, .85fr); gap: 18px; }
.launch-panel, .daily-stats { border: 1px solid var(--line); border-radius: 8px; background: var(--surface); }
.launch-panel { min-height: 300px; position: relative; overflow: hidden; padding: 30px; }
.launch-panel::after { content: "> _"; position: absolute; right: 24px; bottom: 14px; color: rgba(126,224,168,.09); font: 600 92px var(--mono); pointer-events: none; }
.panel-kicker { display: flex; align-items: center; gap: 9px; color: var(--green); font: 600 11px var(--mono); }
.launch-panel h2 { margin-top: 30px; font-size: 28px; }
.launch-panel > p { max-width: 550px; margin: 10px 0 0; color: var(--muted); line-height: 1.7; }
.session-rules { display: flex; flex-wrap: wrap; gap: 18px; margin: 24px 0; color: var(--muted); font-size: 13px; }
.session-rules span { display: inline-flex; align-items: center; gap: 7px; }
.primary-button, .secondary-button { min-height: 44px; display: inline-flex; align-items: center; justify-content: center; gap: 9px; padding: 10px 18px; border-radius: 6px; cursor: pointer; font-weight: 600; }
.primary-button { border: 1px solid var(--green); background: var(--green); color: #0b1710; }
.primary-button:hover { background: #9beab9; }
.secondary-button { border: 1px solid var(--line); background: var(--surface-2); color: var(--text); }
.secondary-button:hover { border-color: var(--line-strong); }
.daily-stats { padding: 24px; }
.stat-line { display: flex; justify-content: space-between; gap: 14px; padding: 13px 0; border-bottom: 1px solid var(--line); }
.stat-line span { color: var(--muted); }
.stat-line strong { font-family: var(--mono); }
.mastery-track, .progress-track { height: 7px; overflow: hidden; border-radius: 4px; background: #0d0f0e; }
.mastery-track { margin-top: 22px; }
.mastery-track span, .progress-track span { display: block; width: 0; height: 100%; border-radius: inherit; background: var(--green); transition: width .3s ease; }
.daily-stats > p { margin: 15px 0 0; color: var(--muted); font-size: 13px; line-height: 1.65; }

.queue-section, .category-progress, .history-section { margin-top: 42px; }
.section-heading { display: flex; align-items: flex-end; justify-content: space-between; gap: 20px; margin-bottom: 16px; }
.section-heading .eyebrow { margin-bottom: 3px; }
.section-heading > span { color: var(--faint); font: 12px var(--mono); }
.queue-list, .question-list { border-top: 1px solid var(--line); }
.queue-item, .library-item { display: grid; align-items: center; gap: 16px; border-bottom: 1px solid var(--line); }
.queue-item { grid-template-columns: 42px minmax(0, 1fr) auto; padding: 16px 0; }
.queue-index { color: var(--faint); font: 12px var(--mono); }
.queue-item strong, .library-item strong { display: block; line-height: 1.55; }
.queue-item small, .library-item small { display: block; margin-top: 4px; color: var(--muted); }
.queue-level { color: var(--yellow); font: 11px var(--mono); white-space: nowrap; }

.session-view { padding-top: 22px; }
.session-toolbar { display: grid; grid-template-columns: 38px minmax(0,1fr) auto; align-items: center; gap: 18px; padding-bottom: 18px; border-bottom: 1px solid var(--line); }
.session-progress-label { display: flex; justify-content: space-between; gap: 12px; margin-bottom: 7px; color: var(--muted); font-size: 12px; }
.session-progress-label span:last-child { color: var(--green); }
.timer { min-width: 78px; color: var(--text); font: 600 20px var(--mono); text-align: right; }
.timer.is-warning { color: var(--yellow); }
.interview-stage { width: min(880px, 100%); margin: 26px auto 0; }
.interviewer-strip { display: grid; grid-template-columns: 42px minmax(0,1fr) auto; align-items: center; gap: 12px; padding-bottom: 18px; border-bottom: 1px solid var(--line); }
.avatar { display: grid; place-items: center; width: 42px; height: 42px; border-radius: 50%; background: var(--surface-2); color: var(--green); }
.interviewer-strip span, .interviewer-strip small { display: block; }
.interviewer-strip small { margin-top: 2px; color: var(--muted); }
.difficulty { color: var(--yellow) !important; font: 11px var(--mono); }
.question-block { padding: 34px 0 28px; }
.question-block h1 { font-size: clamp(25px, 4vw, 38px); }
.mind-toggle { display: inline-flex; align-items: center; gap: 8px; margin-top: 20px; padding: 0; border: 0; background: transparent; color: var(--blue); cursor: pointer; }
.interviewer-mind { margin: 14px 0 0; padding-left: 14px; border-left: 2px solid var(--blue); color: var(--muted); line-height: 1.7; }
.answer-workspace { padding-top: 24px; border-top: 1px solid var(--line); }
.answer-label-row { display: flex; justify-content: space-between; gap: 12px; margin-bottom: 10px; }
.answer-label-row label { font-weight: 600; }
.answer-label-row span { color: var(--faint); font: 12px var(--mono); }
textarea { width: 100%; min-height: 170px; resize: vertical; padding: 16px; border: 1px solid var(--line); border-radius: 6px; background: var(--surface); color: var(--text); line-height: 1.75; }
textarea::placeholder { color: var(--faint); }
.answer-actions { display: flex; justify-content: space-between; gap: 12px; margin-top: 14px; }
.model-answer { margin-top: 28px; padding-top: 28px; border-top: 2px solid var(--green); }
.answer-header { display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.answer-copy { margin-top: 20px; color: #d9dfda; line-height: 1.85; }
.answer-copy p { margin: 0 0 14px; }
.key-points { margin-top: 24px; }
.key-points h3 { margin-bottom: 12px; }
#key-point-list { display: flex; flex-wrap: wrap; gap: 8px; }
.point-check { display: inline-flex; align-items: center; gap: 7px; padding: 8px 10px; border: 1px solid var(--line); border-radius: 6px; background: var(--surface); cursor: pointer; color: var(--muted); }
.point-check input { accent-color: var(--green); }
.point-check:has(input:checked) { color: var(--text); border-color: var(--green); background: var(--green-dark); }
.follow-up { margin-top: 22px; padding: 16px 18px; border-left: 3px solid var(--yellow); background: var(--yellow-dark); }
.follow-up span { color: var(--yellow); font: 600 11px var(--mono); }
.follow-up p { margin: 7px 0 0; line-height: 1.6; }
.self-rating { display: flex; align-items: center; justify-content: space-between; gap: 22px; margin-top: 28px; padding-top: 24px; border-top: 1px solid var(--line); }
.self-rating strong, .self-rating span { display: block; }
.self-rating span { margin-top: 4px; color: var(--muted); font-size: 13px; }
.rating-buttons { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; }
.rating-button { min-width: 112px; min-height: 66px; display: grid; grid-template-columns: 20px auto; grid-template-rows: auto auto; column-gap: 8px; align-items: center; padding: 9px 11px; border: 1px solid var(--line); border-radius: 6px; background: var(--surface); cursor: pointer; text-align: left; }
.rating-button svg { grid-row: 1 / 3; }
.rating-button span { margin: 0; color: var(--text); font-weight: 600; }
.rating-button small { color: var(--faint); }
.rating-again:hover { border-color: var(--red); background: var(--red-dark); }
.rating-good:hover { border-color: var(--yellow); background: var(--yellow-dark); }
.rating-easy:hover { border-color: var(--green); background: var(--green-dark); }

.filter-row { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 24px; }
.filter-button { min-height: 36px; padding: 7px 12px; border: 1px solid var(--line); border-radius: 6px; background: transparent; color: var(--muted); cursor: pointer; }
.filter-button:hover, .filter-button.is-active { color: var(--text); border-color: var(--line-strong); background: var(--surface-2); }
.library-item { grid-template-columns: minmax(0,1fr) auto auto; padding: 18px 0; }
.mastery-chip { min-width: 62px; color: var(--muted); font: 11px var(--mono); text-align: right; }
.mini-action { display: inline-grid; place-items: center; width: 36px; height: 36px; padding: 0; border: 1px solid var(--line); border-radius: 6px; background: transparent; cursor: pointer; }
.mini-action:hover { border-color: var(--green); color: var(--green); }
.empty-state { padding: 52px 16px; color: var(--muted); text-align: center; border-bottom: 1px solid var(--line); }
.empty-state svg { width: 30px; height: 30px; margin-bottom: 8px; color: var(--green); }

.progress-summary { display: grid; grid-template-columns: repeat(3, 1fr); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.progress-summary > div { padding: 22px 18px; border-right: 1px solid var(--line); }
.progress-summary > div:last-child { border-right: 0; }
.progress-summary span, .progress-summary strong { display: block; }
.progress-summary span { color: var(--muted); }
.progress-summary strong { margin-top: 8px; font: 600 32px var(--mono); }
.category-row { display: grid; grid-template-columns: 150px minmax(0,1fr) 54px; align-items: center; gap: 16px; padding: 13px 0; border-bottom: 1px solid var(--line); }
.category-row > span { font: 12px var(--mono); text-align: right; }
.category-bar { height: 9px; overflow: hidden; border-radius: 5px; background: var(--surface-2); }
.category-bar span { display: block; height: 100%; background: var(--green); }
.history-item { display: grid; grid-template-columns: 120px minmax(0,1fr) auto; gap: 16px; padding: 14px 0; border-bottom: 1px solid var(--line); }
.history-item time, .history-item span { color: var(--muted); }

.toast { position: fixed; left: 50%; bottom: 24px; z-index: 20; max-width: calc(100% - 32px); transform: translate(-50%, 20px); padding: 10px 14px; border: 1px solid var(--line-strong); border-radius: 6px; background: var(--surface-2); color: var(--text); opacity: 0; pointer-events: none; transition: opacity .2s ease, transform .2s ease; }
.toast.is-visible { opacity: 1; transform: translate(-50%, 0); }

@media (max-width: 760px) {
  .app-shell { padding: 0 16px 40px; }
  .topbar { grid-template-columns: 1fr auto; height: 64px; }
  .topbar-status { display: none; }
  .mode-tabs { display: grid; grid-template-columns: repeat(4, 1fr); gap: 2px; }
  .mode-tab { min-width: 0; padding: 8px 4px; gap: 5px; font-size: 12px; }
  .mode-tab svg { width: 16px; height: 16px; }
  .tab-count { display: none; }
  .view { padding-top: 30px; }
  .workspace-head { align-items: flex-start; }
  .session-target { display: none; }
  .dashboard-grid { grid-template-columns: 1fr; }
  .launch-panel { min-height: 0; padding: 24px; }
  .launch-panel::after { font-size: 64px; }
  .launch-panel h2 { margin-top: 22px; font-size: 24px; }
  .queue-item { grid-template-columns: 30px minmax(0,1fr); }
  .queue-level { grid-column: 2; }
  .session-toolbar { gap: 10px; }
  .timer { min-width: 62px; font-size: 16px; }
  .question-block { padding-top: 26px; }
  .answer-actions { flex-direction: column-reverse; }
  .answer-actions button { width: 100%; }
  .self-rating { align-items: stretch; flex-direction: column; }
  .rating-buttons { grid-template-columns: 1fr; }
  .rating-button { width: 100%; }
  .library-item { grid-template-columns: minmax(0,1fr) auto; }
  .library-item .mini-action { grid-column: 2; grid-row: 1 / 3; }
  .mastery-chip { grid-column: 1; text-align: left; }
  .progress-summary { grid-template-columns: 1fr; }
  .progress-summary > div { display: flex; align-items: center; justify-content: space-between; border-right: 0; border-bottom: 1px solid var(--line); }
  .progress-summary > div:last-child { border-bottom: 0; }
  .progress-summary strong { margin: 0; font-size: 26px; }
  .category-row { grid-template-columns: 104px minmax(0,1fr) 46px; gap: 10px; }
  .history-item { grid-template-columns: 86px minmax(0,1fr); }
  .history-item span { grid-column: 2; }
}

@media (max-width: 420px) {
  .brand strong { font-size: 13px; }
  .brand small { display: none; }
  .mode-tab { flex-direction: column; min-height: 52px; }
  .workspace-head { margin-bottom: 22px; }
  h1 { font-size: 27px; }
  .launch-panel { padding: 20px; }
  .session-rules { gap: 12px; }
  .interviewer-strip { grid-template-columns: 38px minmax(0,1fr); }
  .difficulty { grid-column: 2; }
  .answer-copy { font-size: 15px; }
}